The present invention relates to a plastic comb separator or cage for ball bearings. The invention is particularly useful for water pumps of motor vehicles although it is not limited to any application. The plastic comb separator retains the balls in their appropriate relative positions.
Assembly of balls and a separator has entailed difficulties in the case of two-row ball bearings, particularly those in the water pumps of motor vehicles, in which two raceways are arranged radially spaced apart, one in a shaft which passes through the bearing and one in a single piece outer ring around the shaft. Difficulties can usually be avoided by using a so called comb separator or cage, which is provided with resilient holding lips that axially fix the separator in the bearing after installation. In one such bearing, which is shown in British Patent 1,370,890, projections are additionally formed in the separator between the holding lips. These projections are adapted for distribution of the balls into substantially separated pockets and for serving as resting surfaces for ejector pins upon manufacturer of the separators.
Because the radial space between the shaft and the outer ring is substantially filled by the separator, it is often difficult to feed lubricant into the bearing. Lubricant is introduced after bearing assembly into the space through which the ball bearing bodies move. The lubricant accumulates between the separator and the seal which is located axially outward of the separator and between the races. When the bearing is placed in operation, the lubricant is forced axially toward the seal, which may cause grease to emerge from inside the seal and may cause the seal to be pushed axially out of its seat.